Andrew and Gail Wallbank with their local church in the background. An ancient law has made them liable for £230,000 worth of repairs to the church. Photograph: Claire Greenway/South West News Service

A couple are being forced to sell their farmhouse because of an ancient law that makes them liable for major repairs at the local church.

Adrian and Gail Wallbank said they had no choice but to sell the farmhouse after being presented with a £230,000 repair bill for St John the Baptist church in Warwickshire.

Under a law dating back to the reign of Henry VIII, whoever owns Glebe Farm is liable for part of the upkeep of the 13th-century church at Aston Cantlow, near Stratford-upon-Avon, where Shakespeare's parents are thought to have been married.

The couple inherited the farm and the title of lay rectors from Gail's father in 1990 and were presented with a bill by the parochial church council shortly afterwards.

After an 18-year legal fight they lost their case in December and are now auctioning the property with a £500,000 guide price. They are hoping to use the money to pay for repairs, buy themselves and whoever purchases the farmhouse out of the liability, and meet their legal fees.

"We really didn't want to sell but we have no choice," said Adrian Wallbank, 64. "We will see very little change from the sale of the house."

The couple are responsible under a "chancel repair liability" clause that arose when the church gave the farm 1.1 hectares (2.75 acres) of land.

In exchange for the land, the owners of Glebe Farm were named as lay rectors and agreed to pay for some church repairs.

The couple, who have seven grown-up children and one granddaughter, were unaware of any repair issues with the church when they inherited the property. But the church council has been chasing them for money since 1990.

Gail, 60, a part-time GP, said: "My father left Glebe Farm to me. We were married in the church but moved away from Aston Cantlow so we rented it out rather than sell it.
"We had been told about some ancient law regarding chancel repair liability but were assured it was a dead law which wouldn't affect us.
"Then one day we received a letter from the church warden informing us we were liable for the repairs to the chancel. We were shocked, to say the least."

Since then the couple, who run a sheep farm in mid-Wales, have spent £250,000 in legal bills fighting to free themselves from the obligation. They finally lost their battle in December when the House of Lords ruled in favour of the church.

Adrian Wallbank said: "It has been a long nightmare and we just want to get shot of the whole thing but we are still waiting to hear from the church over whether we can buy out of the liability. Without that, we will be very lucky to get a buyer."

Chancel repair liability enables approximately 5,200 pre-reformation Church of England and Church of Wales parishes to demand money from owners of particular properties on former monastery land to fund repairs to buildings. These homeowners are called lay rectors, and they are liable for keeping the chancel – the space around the altar at the liturgical east end of the building – windproof and watertight.

The diocese of Coventry refused to comment. Some within the church have previously claimed that many PCCs do not like to enforce the chancel repair liability but are forced to do so because they have to show they have collected all money they are entitled to before being eligible for grants.